In the construction elevator with high-speed inverter based on the single-chip microcomputer and single speed sensor, the response of the automatic smooth layer system is often too slow to guarantee the accurate leveling lift, so the system needs frequent calibration. This paper presents a fuzzy algorithm based elevator automatic leveling system using STC controller. Test results show that, under the condition that the load vary frequently and hoist cage fall inertia, the system can predict elevator weigh...